Jun 7, 2012 9:15 PM

I am sorry for displaying my ignorance but I would be very grateful if someone could identify these little flowers for me. The flowers grow amongst other wild plants in my garden, and are doing rather well this year. There are two varieties, one very pale pink/white, the other violet. They grow on long, slender but strong stems. Curiously, the nearest leaves, which are an inch or so below the flowers, are simply shaped; but further down on the same stems the leaves have a more complex rounded and lobed form, with a scalloped edge.

The petals also seem to be of two kinds. As viewed from the front the inner petals are rounded. Viewed from the side you can see that they extend back into long cones. Between and just behind these rounded conical petals is a second set of long pointed petals, quite simple and leaf-like in shape, radiating outwards. There don't seem to be any sepals.

My last photo shows both kinds of leaves on the stem of one of the white flowers running down into the bottom right corner. Other photos show different views of the flowers.

I'd be really grateful if someone could tell me the name of these flowers, and the names of related plants, and if possible any other info.

Many many thanks Dryopteris. I followed your links and was amazed to see what a large and varied and posh family my little flowers belong to. I also looked up Aquilegia Vulgaris in Wikipedia/Wikimedia Commons (linked in the Wikipedia article) and found useful info and very clear pictures.

The articles I found there point out that both kinds of leaves are tripartite. Among my plants I found what looked like the remains of a seed head, with the rounder more complex leaves about an inch below it on the stem, and no simply shaped leaves. Is it possible that the simply shaped leaves develop into the more complex ones as the plant ages? Also, is there some reason why the simply shaped leaves are much darker than the more complex ones?

Another question I have is - what's happened to the sepals? There are none at the base of the flowers.

Firstly the leaves. Flowering plants often have two forms of leaves, those on the non-flowering parts of the plant and those on the flowering stems or inflorescences. In Aquilegia vulgaris the lower leaves, which are usually referred to as the basal leaves are more complex in shape, as you say, "more complex rounded and lobed form, with a scalloped edge" and also tend to be larger than those further up on the inflorescences. This difference between the basal leaves and the simpler inflorescence leaves means that is always important to look at the lowest leaves possible when identifing a plant in the field, as they can be markedly different not just in size and shape but also in arrangement, e.g. opposite at base but alternate on the inflorescence.

In terms of the relative colour of the leaves - the upper, simpler leaves being darker than the lower basal - leaves in sun will sometimes have two layers of palisade cells containing chloroplasts rather than one.

This allows these leaves to harvest as much light energy as possible which compensates for the leaves which are more shaded. This can make the leaves look a darker green. Even if there is only one layer of palisade cells they can be darker simply because they have many more chloroplasts in them than the lower leaves (for the same reason).

The apparent lack of sepals is a much more exciting question for a plant geek like me (especially as I am interested in plant evolution and the driving force that pollinating insects have had on the evolution of floral structures...) In Aquilegia, and it's sister genera Aconitum (Monkshood) and Consolida (Larkspur) - in the Buttercup family, Ranunculaceae - the sepals have become petal like and have the same colour as the petals. In addition, in Aquilegia and Consolida, all or one, respectively, of the sepals have developed spurs which secrete nectar at their bases. I have anotated one of your pictures to show these structures.

Many thanks indeed for your most helpful and interesting reply. I have a lot of comments and questions – I hope this is the right forum for them.

Many thanks also for the pictures and links. The annotated photo is particularly helpful in sorting out what’s what. I’m astonished to learn that the more leaf-like petals are the “real” petals, and the complicated petals with nectar at their ends are “really” sepals!!!

The film of a developing flower is really beautiful, and seems to confirm something I thought I noticed in the garden, when looking at various stages of the flowers. Am I right in thinking that the leaves nearest the flowers appear for the first time with the flowers, but remain very small, only attaining their full size when the seed pods appear?

Why does the flower need its own leaves nearby? Could it be that they provide extra food for the developing seeds? What happens to these leaves after the seeds have been distributed? Do they develop into rounded leaves or do they just wither away? I am intrigued to hear that the upper leaves of many flowers are often different from the basal leaves, even in their arrangement. I wonder why this is, and why leaves have such varied shapes in general.

Many thanks for explaining about the double layer of palisade cells and/or extra chloroplasts in leaves which are in stronger light.

Sorry to betray my utter ignorance, but do all insect-pollinated flowers produce nectar? Is it usual for the “sepal” part of the flower to be the place where nectar is produced or kept?

I am curious about the positioning of nectar at the far ends of the spurs of Aquilegia. How would this help the flower to ensure pollination? It looks to me as if this arrangement would take most insects past the pollinating area, unless they were quite large. On Sunday morning I saw a bumble bee trying to get at the nectar in the spurs of one of the pale Aquilegia flowers, but from the outside. I saw other insects going onto the stamens of the flower but not going after the nectar from either inside or outside the spurs. Do bees and other insects generally succeed in getting to Aquilegia’s nectar? Are there particular insect customers of Aquilegia Vulgaris as well as of other kinds of Aquilegia?

On quite another subject, in the same area of the garden I also saw a ladybird chasing a white grub around a rose leaf. When the ladybird appeared on the top surface of the leaf the grub disappeared beneath. As soon as the ladybird moved under the leaf, the grub appeared on top. This went on for quite a while. I had to leave, so I didn’t see the end of it.

I’m also curious about the relatives you mentioned of Aquilegia. As it happens I have a great crop of buttercups this year. I’ve just had a look and was thrilled to find unambiguous sepals matching the buttercup’s yellow petals exactly, with just a hint of green in one corner. I never noticed this before! I don’t know if this is just chance, but the Aquilegia flowers are all in the heavily shaded front garden, the buttercups are all in the open sunlit back.

Having begun to take an interest in this, I would like to know a little about the basic family trees of plants. (Sorry for the pun.) Can you recommend a good source of information about this for the utterly ignorant? I would appreciate a guide with good clear illustrations.

Finally, I would like to tell you that I have never before tried to identify flowers, not even the ones you buy in shops, and had no idea how to go about finding out anything about the curious flowers in my jungle. I am therefore enormously grateful to you for all the useful and interesting information, to Dryopteris for identifying my flowers in the first place, and to NHM for providing this forum.

my apologies for not replying to your questions sooner. I have been away on a field trip with no internet access.

Firstly let me apologise for the confusion regarding sepals and petals in Aquilegia...

Mea culpa! I should have used more than one source for my information. The source I did use, a well regarded British flora, described the spurred organs as sepals. I should have gone to Stace! Especially since I was surprised that the sepals should be so ornate and have nectaries...! I should trust my instincts more!

Never mind, thanks to Episcophagus for setting the record straight.

According to Stace - New Flora of the British Isles, 2nd edition - the sepals are petal-like and the petals have long spurs with nectaries.

As I am still recovering from a fortnight of field work with 15 students I hope you will forgive me if I delay responding to your further questions for now. I promise to answer them to the best of my abilities (and having triple checked myself and sources of information...! ) in the very near future.

Many thanks indeed for your recent reply, especially as you have just returned from your field trip with 15 students. I’m very grateful to you for clearing up the petals vs sepals confusion, and for telling me about Stace's New Flora.

I’ve started to take an interest in other wild flowers in my wilderness garden, and am really surprised to see how many different kinds there are.

My Aquilegia have meanwhile developed into fat and healthy looking seed pods. I’ve attached two photos.

I look forward to reading your future brill responses, when you have time.

Aren't, in the Aquilegia-flower, the spurred segments of the inner whorl of the perianth usually considered "petals" and the flat ones of the outer whorl "sepals"? In the photo one can clearly see how the spurs make their way backwards between the segments of the outer whorl.

Jen's annotated photo shows clearly the complex spurred petals as sepals, and the more leaf-like petals as true petals. Is there some way of finding out for sure which are which? Also, sorry for my ignorance, but can you tell me what a perianth is?

The flower can be considered as different types of modified leaves. The innermost, the carpels, make the pistil(s), then outside those comes the stamens. Outside these two is the perianth (that which looks like the "flower" - but is the sterile part of it), which often, but not always, can be divided in inner petals and outer sepals (if they don't differ, they are often called tepals). Thus, as the spurred segments are "inside" the flat segments, the former ought to be called petals (and, in the case of Aquilegia, also is in for instance Flora Europaea and other floras that I have).

Quote from Flora Europaea under Aquilegia (part I , p. 238): "Perianth-segments (sepals) 5, petaloid; honey-leves (petals) 5, more or less tubular, each with a flat limb and a backwardly directed nectar-secreting spur."

Many thanks for your useful information regarding the basic structure of flowers.

Have I got this right? Your latest post quotes Flora Europaea as saying that the petals producing nectar in Ranunculaceae are not really petals but "petaloid" "honey-leaves"? And that you disagree with this because in a different group of flowering plants Flora Europaea makes a different distinction into sepals and petals?

I read somewhere else that some people maintain that none of the petals of Aquilegia are "true petals".

According to your first reply it seems to me that FE implies that this is so as it describes the spurred petals as "honey-leaves", and the flatter petals as "perianth segments (sepals)". They must have a reason for saying this. I wonder what it is.

What is the definition of a true petal? How do botanists decide which are true petals and which are not?

Flora Europaea seems a useful source of information, that is, if ignoramuses like me can understand it. I've looked for it but can only find names of plants, no details. Could you let me have an exact addressfor it?

Since earlier exchanges I've had another look at the actual flowers, or what's left of them following yesterday's gales, to try to see exactly where the different kinds of "petals" on Aquilegia emerge from top of the stem, as the terms"inner" and "outer" are not so clear to me in such a complicated form of flower. It seems to me that one would surely expect the source of the "petals" to be above the source of the "sepals" on the stem. I couldn't see just by looking, so I took some photos, and enlarged them. I've attached some of these in the hope that others might be able to sort out what's what better than I can. One thing I have noticed from my photos is that the leaf-shaped "petals" of Aquilegia seem to have their own little stems.

First of all: Flora Europaea is printed on paper - it is THAT old! It is a five volume work completed in the end of the 1970's (or so), and it costed me a fortune in those days when I was a poor student - nowadays I'm only poor. You can't read it on the Internet.

Second, and to the subject: As I said in my post above, everything in the flower can be regarded as modified leaves. Innermost you have carpels, the female parts of the flower, in one whorl or more. Outside of those you have stamens, the male parts of the flower (in one whorl or more). And outside of those you have the sterile perianth (in one whorl or more).

Leaving the inner fertile whorls aside (these are not completely simple, but we don't care right now), we are left with a perianth. This perianth takes a lot of shapes in different plants. In many ("higher") plants we can easily differentiate between two shapes: sepals and petals. In other (more "primitive") plants we can however not make this simple differentiation. There it is! And there is no such thing as a true petal (or a false), because petals (and sepals) are just definitions of convenience. BUT petals are always inner compared to sepals - however you define them.